Cold Chain for Cut Flowers: Transport and Preservation
The cold chain for cut flowers is the uninterrupted sequence of controlled temperature that runs from harvest on the farm to the consumer's vase. In Colombian floriculture that sequence has six links (harvest and hydration, pre-cooling, grading room, cold room, road transport and international transport), and the goal in all of them is the same: keep the product between 0 and 5 °C (32 and 41 °F) at 90 to 95% relative humidity, depending on the species. It only takes one link to fail for the rest to lose its purpose, because thermal damage cannot be reversed by cooling again.
This article walks through the full preservation process. If what you are interested in is specifically the equipment and the transport leg, we have a separate guide on
Why Colombia depends on its cold chain
Colombia is the world's second-largest exporter of cut flowers, after the Netherlands, and the main supplier to the United States. According to ProColombia, in 2025 the country exported more than 338,000 tons worth over USD 2.376 billion, with more than 1,600 varieties shipped to over 100 destinations.
The difference with the Netherlands is distance. A Dutch flower reaches its main market in hours by road; a flower from the Bogotá savanna or from Rionegro has to cross the continent. That geographic disadvantage is only offset by a cold chain that is better documented and more disciplined than the competitor's. In practice, cold is the sector's competitive advantage, not an incidental cost.
The six links, from the farm to the florist
1. Harvest and hydration
Harvest is scheduled for the cool hours of the day so the stem reaches the grading room with less field heat. Immediately afterwards it is hydrated in solutions that keep the vascular tissue from clogging. There is no refrigeration yet at this point, but every minute of delay is paid for later: the flower keeps respiring and transpiring at ambient temperature.
2. Pre-cooling
This is the critical link. It consists of removing field heat as fast as possible before the product goes into storage. With vacuum cooling, a batch drops from 20–25 °C (68–77 °F) to 2–4 °C (36–39 °F) in about 20 to 35 minutes; with a forced-air tunnel the process is slower but also effective. Vacuum cooling has an extra advantage: it controls free water and reduces condensation inside sleeves and boxes, which is what triggers Botrytis.
3. Grading and packing in a cold room
The room where flowers are graded, bunched and packed should operate cold. If grading is done at ambient temperature, the product warms up again after being pre-cooled and the whole previous step is lost. Boxes must have aligned vent holes so air circulates when they are stacked.
4. Cold room and consolidation
The cold room does not lower the temperature; it holds it. Its job is to maintain the setpoint and the humidity while the order is consolidated. Three things matter here: that relative humidity does not drop (a dry room dehydrates the flower), that species with different thermal requirements are not mixed, and that flowers are not stored next to fruit or vegetables that give off ethylene.
5. Road transport and terminal
The refrigerated trucks that run from the farm to the airport hold 2 to 3 °C (36 to 37 °F). Air cargo warehouses work at 2 to 4 °C (36 to 39 °F). The weak point is the loading dock: every minute a door stays open at a dock without a thermal seal lets in warm, humid air.
6. International transport and destination
Whether in an aircraft hold or in a refrigerated container, this is the longest leg and also the most closely monitored. Flowers shipped by sea from Cartagena or Santa Marta spend several days in transit; flowers flown out of El Dorado reach Miami in a matter of hours. In both cases the chain ends in the importer's cold room, not at the destination terminal.
Target temperature by variety
Post-harvest practice groups flowers by their sensitivity to chilling injury: tolerant (0 to 2 °C / 32 to 36 °F), subtropical (2 to 8 °C / 36 to 46 °F) and tropical (12 to 16 °C / 54 to 61 °F). These are the most widely used handling references, and the sign that gives away a broken chain:
| Variety | Target temperature | Sign of a broken chain |
|---|---|---|
| Rose | 0.5 to 2 °C (33 to 36 °F) | Bent neck, bud that does not open, dehydrated outer petals |
| Carnation and mini carnation | 0 to 1 °C (32 to 34 °F) | Premature opening and petal drop from ethylene exposure |
| Chrysanthemum and pompon | 0 to 2 °C (32 to 36 °F) | Yellowing foliage and loss of turgor |
| Hydrangea | 2 to 5 °C (36 to 41 °F) | Wilted flower head within the first hours |
| Alstroemeria | 2 to 5 °C (36 to 41 °F) | Yellow leaves and aborted buds |
| Anthurium and heliconia | 12 to 17 °C (54 to 63 °F) | Browning and dark spots from chilling injury below 10 °C (50 °F) |
These are reference ranges: each variety, cut stage and market may require an adjustment agreed between grower and customer.
Where the chain usually breaks
- Between harvest and pre-cooling. This is the most common gap and the most costly. Every hour of warm flowers takes days off vase life.
- At handovers. Docks, consolidation platforms and terminal yards are where the product is exposed to the environment while it changes hands.
- Through ethylene build-up. This is not a temperature problem but an air problem. Without air renewal, the ethylene the flower itself gives off (and any neighboring product) speeds up senescence even when the thermometer reads fine.
How the cold chain is documented
A cold chain that is not recorded cannot be defended against a claim. The minimum documentation includes continuous temperature and humidity logs in the cold room and in transit, taken with calibrated instruments; data loggers inside the cargo, not just the equipment's own reading; and batch traceability that lets the journey be reconstructed hour by hour.
On top of that comes the phytosanitary framework: in Colombia, the ICA (Colombian Agricultural Institute) requires the producing farm to be registered for export and issues the phytosanitary certificate that accompanies each shipment, processed before the cargo leaves the farm for the port or the airport.
Frequently asked questions
What happens if the cold chain breaks for a few hours?
The damage is cumulative and irreversible. Cooling again stops the deterioration, but it does not recover the vase life already used up. That is why the indicator that matters is not the average temperature of the trip, but the total time out of range.
Which link is the most important?
Pre-cooling. It is the only step that removes heat instead of merely holding it, and it determines the condition in which the product enters all the following links.
Can flowers and fruit be transported together?
It is not advisable. Fruit such as bananas and avocados give off ethylene, and most cut flowers (carnations in particular) are very sensitive to that gas. Their optimal temperatures also rarely coincide.
What relative humidity do cut flowers need?
Between 90 and 95% in most cases. Below 80% the flower dehydrates; with free water condensed on the petals, Botrytis appears. The balance is achieved with high humidity and no condensation, not simply by wetting.
How does the equipment that holds the cold work?
The principle is the same as a cold room, applied to mobile equipment. We explain it in detail in
Shipping flowers or other perishables? See our refrigerated containers with precise temperature control.